This invention concerns a semiconductor device having a thin insulation film for forming a non-volatile memory or a capacitive component.
In a semiconductor device having polycrystalline silicon electrodes and wiring, it is known to use insulation film, polyimide film and thermally oxidized film of polycrystalline silicon formed by a chemical vapor deposition (CVD) process as the material for insulating the polycrystalline silicon electrodes and wiring from the electrodes and wiring formed thereover (for example, Al, polycrystalline silicon, etc. are used as the eletroconductive material).
However, in the case of using a thin insulation film with a thickness of less than 1,000 .ANG. as the insulation material, a thermally oxidized film of polycrystalline silicon has been used since such provides a preferable insulating performance and good control of the film thickness.
Due to the demand of making the structure finer and the operation speed higher for IC devices in recent years, polycrystalline silicon as the material for the electrodes and wiring has been gradually replaced with polycide comprising a two layered structure of polycrystalline silicon and metal silicide. However, thermally oxidized films of polycide exhibit poor film thickness uniformity and unfavorable insulating performance. Accordingly, since the insulating performance of a thin insulating film of less than 1,000 .ANG. thickness formed by thermally oxidizing the periphery of polycide used as the wiring and electrodes is also poor, it has not been possible to use the polycide as the material for the electrodes and wiring of a semiconductor device.
In a structure in which a polycide is used as the electrode and wiring of a lower layer, and an electrode and wiring of an upper layer is formed thereover with a thin insulation film therebetween, a thermally oxidized film formed by thermally oxidizing the periphery of the polycide has a poor film thickness uniformity and a not so favorable insulating performance. Accordingly, since the insulating performance of a thin insulating film of less than 1,000 .ANG. formed by thermally oxidizing the periphery of the polycide is also poor, it has not been possible to use the polycide as the material for the electrodes and wiring of a semiconductor device. Therefore, there has been a problem that it is impossible to obtain a higher operation speed by decreasing the resistance of the electrodes and wiring in such a semiconductor device.